Carburetor



. 40 advantages indicated above.

Patented July 10, 1934 CARBURETOR Emil Schimanek, Budapest, Hungary, assignor to Socit du Carburateur Bleriot, Paris, France Application March 31, 1933, Serial No. 663,825

In France June 4, 1932 Claims. (Cl. 261-50) In French Patent No. 611,742 of 26th February 1926 a carburetor was described ,in which the partial vacuum existing in the vaporizing chamber, that is to say, at the place where the air and 5 fuel are mixed, remains constant. The car-'- buretor comprises aspecial member, for example a piston having a certain degree of free play, which automatically ensures theconstancy of the partialvacuum independently of the load and of the speed of the engine. In this carburetor it is possible to regulate the composition of the mixture by the rotation of this same member; in fact, this rotation has for result to vary the section of the orifice through which the air penetrates into the vaporization chamber. Thus, in the case of aircraft engines for example, the density of the air varying, as is well known, rapidly with the altitude, this rotation enables the greatest eificiency to be obtained'with the smallest consumption. The French patent in question also specifies a second method of regulation. This method consists in varying by suitable adjustment, the inlet orifice for the fuel, for example by the-displacement of a needle.

.25 Tests effected-by the applicants have shown,

concerning aviation, that:

1. If it is desired to effect a regulation by acting exclusively on the arrival of air, on account of the rotation of a member such as the piston indicated above, it becomes necessary, at high altitudes, to effect a very considerable rotation of this piston;

2. Regulation by displacement of the needle,

although possibly suflicient on the ground, is no,

longer suitable for high altitudes, for, in the latter case, the composition of the mixture varies at the same altitude according to the speed of the engine.

The present invention has for its object an improved carburetor which is free from the dis- Its main characteristic consists in the conjugation of the regulating means which in the carburetor forming the sub-- of carburetors constructed according to the invention.

Figure 3 is a, vertical section, Figure 4 a plan view with partial horizontal section of a modification.

Figure 5 illustrates a detail.

Fig. 6 is an enlarged vertical sectional detail of the upper part of the arrangement shown in Fig. 3.

The body of the carburetor 1 comprises a cylinder 2' in which the piston 3 can slide freely on towards the top and towardsthe bottom; moreover, this piston can receive a movement of rotation which is communicated to it by thelever 5 in which the finger or spur 4 engages. The fuel, maintained at a certain level in the tank 6, passes through the disc 7, the central orifice of which is 'more or less closed by a conical needle 8. It

mixes with the primaryair arriving through the holes 9 and 10. 'Theprimary mixture becomes engaged in the hollow rod 11 of the piston and enters the vaporizing chamber 13 through the orifice 12. On the other hand, the air enters into stopper 19 which is fixed to the operating lever 5. The latter is connected to the upper end of the cylinder 2 by screw threads 20; it will be seen that by turning the piston 3 the needle is at the same time moved towards the top or towards the bottom.

The position of the needle 8 can be altered by hand by acting on the stopper 19 which comprises screw threads 21 without touching the piston 3.

In the constructional modification shown in Figure 2 the fuel mixed with primary air does not rise in the piston rod, but does so in the fixed pipe 30; it penetrates into the latter through the disc 31; on the other hand, the needle 32 is moved by the piston 33. The needle is fixed to the tongue 34 traversing the aperture 29 of the cylinder, and this same tongue is fastened to the rod 35 of the piston 33 and prevents the latter from turning.

The piston is kept in position by the finger or spur 36 of the operating lever 37. By means of this lever it is possible to turn the piston. The piston and its rod are assembled by a screw connection 38. When the piston is turned the regulating shutter 39, which is integral therewith, covers or uncovers the aperture 29 of the cylinder 40 but, at the same time, the rod 35 of the piston ascends or descends relatively to the latter on ac count of the presence of the screw threads 38.

The needle can be moved separately by hand by acting on the let-in screw or screw-threaded stopper 42. The position of the needle 32 relatively to the disc 31 can also be modified by hand by turning the tube 30; in fact, the latter and the disc 31 move vertically, because the tube 30 is connected to the body of the carburetor by a thread 43.

Figures 3, 4 and 5 show by way of example another constructional form of the invention.

The needle 50 is suspended from a lever 51 which can swing round a small shaft 52 and is guided at its other extremity in the inclined groove 53 of the piston 54 (see Figure 5).

The shaft 52 is carried by a head 55 placed between the branches of the lever 51 in the form of a fork so as not to be able to turn in the latter. The head is connected to the rod 56 of the piston by screw threads 5'7.

When the pin 58 is in place, if the piston is turned, the needle moves vertically, towards the top or towards the bottom, according to the inclination imparted to the lever 51 carrying the said needle. (This lever 51 is guided at its extremity by the oblique groove 53 of the piston).

When the pin 58 is removed the displacement of the needle is also obtained by the rotation of the rod 56, the piston 54 being maintained fixed.

I claim:

1. A carburetor comprising a body partitioned internally to form an air inlet chamber and a mixing chamber, said partition having an opening providing communication between said air and mixing chambers, a fuel chamber in said body, a fuel conduit leading from said fuel chamber and communicating with the mixing chamber to discharge fuel thereint'o, a piston mounted for rotatable and vertical movement within the upper part of the air chamber to control the effective area of said opening, said fuel conduit also being provided with means to admit primary air, a needle valve for controlling the passage of fuel through the conduit, and means for operably connecting the needle valve to the piston.

2. A carburetor as claimed in claim 1, wherein the means for operably connecting the needle valve and piston also include means for independently adjusting the needle valve.

3. A carburetor as claimed in claim 1, wherein the needle valve is directly and adjustably connected to the'top of the body and wherein the fuel conduit is constructed in the form of a hollow rod for the piston.

4. A carburetor as claimed in claim 1, wherein a rod is provided for the piston and is adjustably connected therewith, and wherein the means for connecting the needle valve to the piston includes an arm connected to the piston rod and having adjustable connection with the needle valve.

5. A carburetor as claimed in claim 1, wherein the means for operatively connecting the needle valve to the piston include a pivotally mounted lever from one end of which the needle valve is pivotally suspended the other end of the lever operating in an inclined groove in the piston.

EMIL SCHIMANEK. 

